Paint spray valves for paint spray installations

ABSTRACT

This invention is concerned with control valves for supplying paint to paint installations utilizing a plurality of different color paints. The control valve may be adapted to various systems by utilizing a disclosed flow housing which forms an elongated flow passageway when a number of valves are assembled. The control valve may also be adapted to recirculate paint during periods of valve inactivity to prevent clogging due to the solidification of stagnant paint. The control valve of the invention includes structural innovations, such as manual means for activating a disabled valve. The invention is also directed to a system for automatically purging the installation when the paint supply to a valve is cut off.

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[54] PAINT SPRAY VALVES IFQR lPAlll l'll [56] ll telere Ci SPRAYHNSTALLATHUNS UNITED STATES PATENTS [72] Wham Wlggms, Fame, 3,334,6488/1967 Probst ..137/240 M [73] Assignee: The Gymmat tjorporation,Stratfield,

Conn- Primary Examiner-Henry T. Klinksiek Attorney-Mandeville andSchweitzer [22] Filed: Oct. l, 1970 [21 Appl. No.3 77,133 [571 Thisinvention is concerned with control valves for supplying RelatedUS'Apphcatmn Dam paint to paint installations utilizing a plurality ofdifierent [60] Division of Ser. N0. 676,824, oct. 20, I967, Pat. N0.color paints The control valve may be adapted to various 3,572,366,which is a continuation-in-part of Ser. NO. systems y utilizing adisclosed flow housing which forms an 440,736, Mar. 18, 1965, Pat, N()3,348,774 elongated flow passageway when a number of valves areassembled. The control valve may also be adapted to recirculate 52 us.(:1 ..137/24111, 137/556 paint during Periods of valve inactivity toPrevent clogging due 51 1m. (:1 ..111611; 511/4111, Fl6k 37/00 to thesolidification of stagnant Paint The control valve of the [581 Field 611Search ..137/15, 238, 240, 556; invention includes Structuralinnovations, Such as manual 239/112 means for activating a disabledvalve. The invention is also directed to a system for automaticallypurging the installation when the paint supply to a valve is cut off.

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' INVENTQR.

I RICHARD F. WIGGINS ATTORNEYS Patented March 14, 1972 3,648,717

4 Sheets-Sheet a FIG. 3

INVFN'TOR. RICHARD F WIGGINS WiW ATTORNEYS Patented March 14, 1972 4Sheets-Sheet R INVENTOR RICHARD F. WIGGINS ATTORNEYS Patented March 14,1972 4 Sheets-Sheet 4 QwNEDmmwmm ATTORNEYS PAINT SPRAY VALVES F 01RIPAHNT SPRAY INSTALLATHONS CROSS REFERENCE TO RELATED APPLICATIONS Thisapplication is a division of copending application Ser. No. 676,824,filed Oct. 20, 1967, now U.S. Pat. No. 3,572,366, which is acontinuation-in-part of application Ser. No. 440,736, filed Mar. 18,1965, now U.S. Pat. No. 3,348,774, issued Oct. 24, 1967.

BACKGROUND AND SUMMARY OF THE INVENTION This invention is concerned withpaint supply systems for use in multi-color spray painting installationssuch as those installations described in my previously mentioned U.S.Pat. No. 3,348,774. More specifically, the invention provides a controlvalve for selectively supplying paint or solvent to the spray guns of aspray painting installation and supply systems including an assemblageof control valves to accomplish various objectives which will bediscussed in detail hereinafter.

In accordance with a specific aspect of the invention, a control valveis provided with a flow housing section having a through passageway andattaching means for connecting the flow housing to that ofa similarvalve. When connected in this manner, the individual flow housingpassageways form a continuous supply passageway of relatively uniformcross section which is selectively fed by all of the supply valves andwhich in turn ultimately feeds the spray guns of the spray paintinginstallation.

Each individual control valve flow housing passageway can be defined, inpart, by a longitudinally movable valve head which is on the lower endof a valve stem and controls the flow of fluid into the flow housingpassageway. The valve head seats in a valve seat located in the lowerend ofa valve housing that contains a passageway for the valve stem.

The supply valve farthest upstream may be used as a solvent supply valveto supply purging fluid to the system during the purging cycle. Sincethis single purge fluid supply valve is upstream from the paint supplyvalves, all lines feeding the spray guns and contaminated with thepreviously used paint will be flushed by the solvent supplied by thisvalve.

Each control valve of the assemblage is provided with two conduitscommunicating with each other in the valve housing passageway and withthe flow housing passageway. These conduits typically are used as paintand solvent inlet nozzles with the solvent supply nozzle disposed tosupply solvent to all internal surfaces of the valve contacted by thepaint and thereby flush the valve during the purge cycle. Typically thesolvent inlet nozzle is disposed in the valve upstream from the paintsupply nozzle.

The provision for purging each individual valve after use permits anassemblage comprising two paint supply valves as previously described,with a purge or solvent valve if desired, to be used for alternativelysupplying three or more different color paints to the spray guns. Bycompletely flushing the paint supply system including the valvesupplying the color it is desired to discontinue using, the second paintsupply valve can be used to supply the color paint it is then desired tospray, and the now flushed, previously used supply valve is renderedinactive and prepared to supply a third color paint when desired. Itshould be apparent that this sequence can be repeated for as manydifferent colors as one desires. A more detailed description of atypical change cycle as contemplated by the invention will be found inmy above referred to U.S. Pat. No. 3,348,774, and a discharge system foruse in conjunction with the color change cycle is described in detail inmy U.S. Pat. No. 3,458,133, issued July 29, 1969.

Where economically justified, an assemblage of valves of the typementioned above may include a separate, individual control valve foreach of a multitude of different color paints. Such a system has theadvantage of being operable on a substantially fully automated basis,since color changes may be effected without disconnecting andreconnecting paint supply lines. Maintenance of a system of this typecan also be minimized by continually circulating paint through inactivevalves, thereby preventing clogging of the valve by the solidificationof stagnant paint.

In a system wherein a separate paint supply valve is provided for eachcolor paint, it is not necessary to purge the valve itself during thepurging cycle. lt is therefore practical, in such an installation, toutilize the solvent inlet nozzle to recirculate the paint back to thepaint supply receptacle when the valve is inoperative.

In accordance with another aspect of the invention, a pair of controlvalves of the general type previously described may be joined toopposite ends of a simplified connecting member, advantageously having alongitudinal passageway and a traverse outlet flow passage. The valvesare oriented to position their respective valve seats opposite oneanother and thereby forming a chamber, the ends of which are defined bythe two valve seats and the sides of which are defined by the walls ofthe connecting member. The transverse outlet flow passage of theconnecting member is located in the chamber between the respective valveseats, and ultimately feeds either paint or solvent to the spray guns ofthe spray painting installation. In effect, the connecting member servessubstantially the same function as the previously described flowhousing, with attendant advantages to be described shortly.

The last described assemblage of control valves can be usedadvantageously in a multi-color paint spray system utilizing three ormore different colors. It should be noted that by utilizing thisassemblage in a multi-color paint spray installation, a separate purgefluid supply valve is not required because of the facing relationship ofthe two control valves. During the purge cycle, the just-used valve ispurged by solvent which also flushes the chamber formed in theconnecting member up to and including the seated valve seat of the othercontrol valve. The solvent then flows from the chamber to the spray gunsthrough the traverse outlet flow passage and connecting lines andeventually to a purging discharge system.

After the purging cycle is completed, the previously inactive controlvalve is activated and supplies a second color paint to the system. Thenow inactive valve can be connected to a third color paint supplyreceptacle during the spray cycle of the second color paint and thus beready for use when the system is purged of the second color paint.

Advantageously, and in accordance with the invention, each solvent inletincludes a check valve to prevent paint supplied to the control valvefrom backing; up into the solvent supply system. In conjunction with thesolvent inlet check valves, the paint is supplied to the control valvesat a higher pressure than the solvent, thereby preventing solvent flowinto the valve when the paint is being supplied and automaticallycausing solvent to flow into the control valve through the check valvewhen the paint supply is shut off. A significant aspect of the inventionis, therefore, the provision of a purging system that automaticallysupplies solvent to the paint spray installation in response to theshutting off of a paint supply.

Another significant feature of the invention is the provision, in avalve arranged to be remotely actuated by pneumatic or other means, ofanovel, manually operated mechanism for activating a control valve thathas become inactive due to a mechanical failure in its activationmechanism. Such a failure can possibly occur with any type of activationmechanism and may be expected to occur periodically with an air bellowsmechanism, as is typically and advantageously used in conjunction withthe valves of this invention. When an activation bellows fails, thevalve head seats and cuts off the supply of paint to the system. Sincemulti-color spray paint installations of this type are used to paintarticles moving on a production line, it is highly desirable to continuespraying the particular color in use until the end of its run even aftera breakdown occurs and without having to stop the production line torepair the disabled valve. The manually operated mechanism of theinvention, while being simplified and inexpensive, permits the disabledvalve to continue supplying paint during its active portion of thepainting cycle and to be subsequently repaired while it is inactive.This aspect of the invention, therefore, saves valuable production timeby not forcing a production line shut down while the disabled controlvalve is repaired.

BRIEF DESCRIPTION OF THE DRAWING For a better understanding of theinvention, reference should be made to the following detaileddescription and drawing, in which:

FIG. 1 is a top plan view of an assemblage of control valves inaccordance with the invention;

FIG. 2 is an elevation view of the assemblage of FIG. 1;

FIG. 3 is a cross-sectional view of an individual control valve of theinvention, taken along line 3-3 of FIG. 2;

FIG. 4 is a partial cross-sectional view of a modified control valve ofthe invention, taken along line 44 of FIG. 5;

FIG. 5 is a partial cross-sectional view of an assemblage of modifiedcontrol valves in accordance with the invention, taken along line 5-5 ofFIG. 4; and

FIG. 6 is a partial cross-sectional view of an advantageous form of twovalve paint supply systems in accordance with the invention.

DESCRIPTION OF A PREFERRED EMBODIMENT With reference now to FIGS. 1-3,there is shown a control valve assemblage generally indicated by thereference numeral 24, according to the invention, which is particularlysuited for incorporation in the spray paint system disclosed in mybeforementioned U.S. Pat. No. 3,348,774. The illustrated assemblageincludes four control valves of substantially identical construction,the individual features of which are illustrated in FIG. 3.

Advantageously, each of the primary control valves has two inletscontrolled by the valve elements and arranged to discharge fluid intothe main flow passage 26 when the associated primary control valve isopen. Thus, the purge valve 27 has its inlets connected to a purging airsupply line 45 and a purging solvent supply line 46. The air supply line45 is connected through a check valve 47 and a solenoid operated controlvalve to an air supply line. The arrangement is such that, when thesolenoid operated control valve is open, air under pressure is suppliedto the purge valve 27, for discharge into the system upon opening of thepurge valve. The solvent supply line 46 is connected through a checkvalve 49 and a shut-off valve to a solvent supply container. Each of theprincipal control valves 17 and 27-29 is pneumatically or electricallyactuated and, for this purpose includes an actuating bellows 30-33connected to a source of compressed air by means of control lines suchas 34 shown in conjunction with valve 17. The control lines can bedetached from the actuating bellows 30-33 by the use of quick disconnectcouplings 64, 65, thereby permitting a control line to activate morethan one control valve. Each valve includes a flow housing 80 providedwith a longitudinal flow passage 81 extending from one end to the other.At its end extremities, the flow housing of each valve is provided withoutwardly extending flanges 82 adapted to be bolted or otherwise securedto the similar flanges of adjacent valves or to mounting brackets 83.

In the upper portion of each of the flow housings 80, there is amachined recess 84 which extends downward and into open communicationwith the longitudinal flow passage 81, which is horizontally oriented inthe illustrated arrangements. A valve housing 85 having a downwardlyprojecting machined boss 86 is secured in fluid-tight relation to theflow housing 80, with the boss 86 being received in and maintained insealed relation with the recess 84. The valve housing 85 is provided atits lower end with a hardened and ground valve seat 87 of annular form,the opening of which communicates with a lower, primary valve passage 88and an upper, secondary valve passage 89.

An elongated hardened and ground valve stem 90 extends through the valvepassages 88, 89, being slidably guided in the secondary valve passage89. At its lower end, the valve stem has a conical valve head 91 whichcloses against the annular valve seat 87 in the manner shown, such thatthe lower surface 92 of the valve head forms part of the wall of theflow passage 81. The arrangement is such that the flow passage 81, fromone end to the other of the flow housing 80, is smooth and relativelyuniform in cross section, affording a relatively minimum opportunity toform eddies and collection pockets which would reduce the efficiency ofclean-out.

At its upper end, the valve stem connects with a bellows element 93which is located within a bellows housing 94 and forms a seal betweenthe housing and the valve passage 89. The bellows is normally urgedupward by a spring 95, but is actuated in a downward direction byintroduction of pressure fluid (air) into the bellows chamber 96 througha quick disconnect control air fitting 97.

The specific valve illustrated in FIG. 3, which is the downstream paintvalve 29, has its flow passage plugged on the downstream side and isprovided with a fitting 98 in its bottom outlet port 23, which causesthe fluid flow to be discharged into the supply line 21. The valve isalso connected to the solvent line 61, through stop cock 59 and to thepaint supply line 55 (downstream of the quick disconnect fitting)through the stop cock 57. The paint supply discharges into the primaryvalve passage 88, while the solvent supply discharges into the secondaryvalve passage 89, upstream of the paint supply. An upstream paint valve28, of similar construction to the valve 29, is connected to the solventsupply through a solvent line 60 and a stop cock 58, and to a paintsupply through a quick disconnect fitting 62 and stop cock 56, from apaint line 54.

In accordance with one aspect of the invention, a complete installationadvantageously incorporates a unitized bank of primary control valves,including a discharge valve 17 and a purge valve 27, as well as aplurality of paint valves 28, 29. Actually, the discharge valve 17 maybe located elsewhere in the installation, without inconvenience, but itis particularly advantageous for the purge valve and paint controlvalves to be arranged in a unitized bank, as shown inFIGS. 2 and 3.Thus, a series of primary control valves including the purge valve andas many paint control valves as may be desired to be used in the systemare assembled in end-to-end relation, with their respective flanges 82in abutting relation and secured together in a fluid-tight manner bybolts or other suitable means (not shown). The arrangement is such thatthe flow passages 81 of the respective flow housings are aligned and incommunication to form an elongated, relatively smooth passage ofrelatively uniform cross section from one end to the other.

In a complete assembly of valves, a suitable plug 99 is inserted in theupstream end of the flow passage of the purge control valve 27, while asimilar plug 100 is inserted in the downstream end of the flow housingof the downstream paint valve 29. Other suitable plugs close off two ofthe three openings of the flow housing for the discharge valve 17, whilethe remaining opening, advantageously at the bottom, is connected withthe discharge line 18 through a fitting 101. The discharge valve is thusisolated from the other valves of the installation.

As shown in FIG. 2, suitable plugs 102 close off the bottom outlets ofthe upstream control valves, while the discharge outlet 23 in the bottomof the downstream control valve 29 is connected with the supply line 21through the fitting 98.

The entire bank of control valves, as shown in FIGS. 1 and 2, forms aconvenient unitary assembly, which is secured at each end to suitablemounting brackets 83.

Referring to FIGS. 4 and 5, a valve of the general type previouslydescribed is shown with certain modifications which make it suitable foruse in multi-color paint spray installations wherein a separate supplyvalve is provided for each color. Such an installation may be operatedon a substantially fully automated basis, and it is, therefore,advantageous to provide, in a valve for such service, means effective tominimize breakdown and to enable breakdowns, should they occur, to beremedied with a minimum loss of production time.

The valve shown in FIGS. 4 and 5 includes, as one modified feature, apacking 103 sealing off the valve passage 09 upstream from connections1141, 117. This sealing element has the effect of preventing a fluidflow into the control air line 97 through the bellows element 93 if thebellows element should happen to fail during operation, but does notinhibit longitudinal movement of the valve stem 90. In this respect, itwill be understood that the repeated flexures to which the bellowselements are subjected in use renders them inherently susceptible tofailure after a time.

In the event of a breach in the bellows element 93 during operation ofthe valve, the air pressure inside and outside the bellows element willequalize causing the bellows element to assume its upwardly extendedposition by the action of the spring 95. This would cause the valve stem90 to move upward, seating the valve head 91 in the valve seat 07 andstopping the flow of paint into the paint spray system.

Paint spraying installations of this type often are used to paintobjects moving on a production line. In a complex system, apredetermined number of objects may be painted a particular coloraccording to a computerized plan, after which the paint spray system ispurged and a second group of objects is sprayed with a different colorpaint. With this in mind, it is apparent that if a supply valve shouldbreak down during the period it is supplying a particular color paint tothe spraying system, the entire production line might have to be shutdown while the valve is repaired. Obviously, this could be a very costlyand undesirable procedure. Losses due to such shut downs are minimizedby the inclusion in the valve of this invention of a single andconvenient manually operated mechanism, shown generally as 104 in FIG.1, for immediately reactivating a disabled valve without having to shutdown the production line. The disabled valve is permitted to completeits cycle with an inconsequential interruption in production and can besubsequently repaired during a period of inactivity.

The manually operated mechanism 104 comprises a main sleeve 107,threadably connected to the top of the bellows housing 94, and cap 105,having a closed upper end and threadably mounted on the main sleeve 107.The cap 105 has a recess, closed by an abutment surface 112, into whichan indicator stem 108 projects when the valve head 91 is seated. Theindicator stem 100 is fixed to the upper section of the bellowsactuating mechanism 110 and reflects the position of the bellows element93.

During operation of the valve, pressurized air is supplied to thebellows chamber and urges the bellows element 93 downward, which in turnmoves the valve stem 90 downward, causing the valve head 91 to unseat.The indicator stern 1011 also moves downward and at least partially outof the cap recess and away from its end surface 112. In the event of abreach in the bellows element 93 during operation, the bellows elementwould be moved upward by the spring 95 due to the equalization ofpressure inside and outside of the bellows element. Consequently, thevalve head 91 is seated by this upward movement of the bellows element,and the paint supply is cut off from the spray painting system. Theindicator stem 100 also moves upwardly and toward an abuttingrelationship with the abutment surface 112. The condition of the valvecan be determined by observing the indicator stem 100 through a window113 provided in the cap 105 through which the upper end ofstem 100 isvisible when valve head 91 is seated.

To reactivate a disabled valve, the cap 105 is unscrewed and removedfrom the sleeve 107, thereby permitting a spacing collar 106 to beremoved. The cap 105 is thereafter replaced and screwed down as far asit will go. Since the spacing collar is no longer present, the cap 105is finally seated farther down on the sleeve 107, as shown in the righthand portion of FIG. 5. In accordance with the invention, the collar 106has a thickness approximately equal to the longitudinal distance thevalve stem must move to fully open the valve head 91. Ac-- cordingly,when the cap is replaced after removal of the spacer section, the stem100 is pressed downward this distance by contact between the upper endof the stem and the abutment surface 112 of the cap. This downwardmovement of stem 100 is transmitted directly to the valve stem 90,through a connecting element 109. This effects unseating of the valvehead 91 and enables continuation of the supply of paint to the paintspray system. The spring 95 urges the indicator stem upwardly and keepsit in solid contact with the cap while the valve is being manuallyactivated. A suitable packing 111 is disposed around the indicator stem100 to prevent the loss of air pressure in the bellows chamber 96through the window 1 13 during normal valve operation.

As previously stated, the control valve described above may beadvantageously used in a multi-color paint spray installation having aseparate control valve for each color of paint. In such a system, it isnot necessary to have a solvent inlet line leading to each of thecontrol valves, since the valve does not have to be flushed during thepurging cycle. This permits the conduit normally used to supply solventto the valve to be used to recirculate paint while the valve is inactivethereby avoiding settling or stagnation of the paint in the system.

Thus, in the system shown in FIG. 4, .a paint inlet connection 114,feeds paint from a paint supply receptacle 115 to the valve passageway00 through first paint conduit 116. A suitable pump (P), located in theconduit 116 supplies the necessary pressure. When the control valve isinactive, the valve head 91 is seated preventing paint supplied throughthe inlet connection 1141 from flowing into the paint sprayinstallation. A paint outlet connection 117 communicates with the paintinlet connection 111 in the valve passageway 88 and is connected to thepaint supply receptable by a second conduit 110. A pressure regulator(PR) is located in the second conduit line enabling the spray pressureto be maintained according to requirements.

During periods of valve inactivity, the pump (P) continuously circulatespaint through the valve and back to the supply receptable at a constantpressure determined by the pressure regulator (PR), so that the paint isat all times in a condition for immediate use.

When the valve is activated, paint supplied to the passageway 00 flowsinto the flow housing passageway 01 and eventually to the spray guns(not shown). It should be noted that, typically, even when the controlvalve is supplying paint to the system, a portion of the paint will berecirculated back to the paint supply receptacle 115, because the nozzledischarge rate typically will be less than the capacity of the pump.

Referring now to FIG. 6, a paint supply system incorporating a pair ofcontrol valves of the general type previously described, is shown. Thissystem is most advantageously suited for use in a multi-color paintspray installation handling three or more different colors of paint withonly two control valves.

A pair of control valves 121}, 129, generally as previously describedexcept without the allocated flow housing 80, are disposed opposite eachother and connected together by a connecting member 119. The connecting;member 119 has a longitudinal internal passageway, which in conjunctionwith the valve head 91, forms a chamber 121. A transverse flow passage122 is provided in the connecting member 119 to bring the chamber 121into eventual communication with the spray guns of the spray paintinstallation. The arrangement is such that pressurized paint, suppliedto an activated control valve through either of paint supply lines 123or 1241, flows into the chamber 121, and then out through the transversepassageway 122 into the spraying apparatus (not shown).

Each of the vales 128, 129 also is supplied with solvent from apressurized source thereof, through solvent supply lines 125. During acolor change cycle, as will 'be described, a just used valve may beflushed out with a solvent flow, which then continues through thedistribution lines to flush out the entire system of the previously usedpaint and ready the installation to handle a new color of paint.

A significant specific feature of the invention is the provision ofcheck valves 1215 in each of the solvent and paint inlet connections127, 130. The check valves 126 are oriented to permit flow only into thecontrol valves. in conjunction with this feature of the invention, thesystem includes paint and solvent pressure regulators 141, 142, wherebypaint is supplied to the control valves at a higher pressure than thesolvent. Because of the higher supply pressure, solventcannot flow intothe valve while paint is being supplied, and the check valves 126associated with the solvent connections 127 prevent the higher pressurepaints from backing up in the lower pressure solvent lines. Thearrangement provides a substantially automatic purging system thatimmediately responds to the shut-off of paint in an active control valveto supply purging solvent to the valve and to the distribution lines.

Thus, when the supply of paint to the valve is shut off, pressurizedsolvent is no longer held back by the higher pressure paint andconsequently automatically flushes the valve and associated spraypainting apparatus. It is apparent that this assemblage of controlvalves does not require a separate purge valve for flushing the systemduring the color change cycle.

At any given time during the operation of this system, one of thecontrol valves is active and the other inactive. When the valve 128 isactivated, for example, paint B is supplied to the valve through asupply line 123, paint inlet connection 130, and associated check valve126. When it is desired to discontinue spraying paint B and to commencespraying paint A, a shut-off valve V is closed, cutting off the supplyof paint B. At this point, the valve head 91 of control valve 128 isstill unseated and remains so until the end of the purge cycle. Ofcourse, the valve head 91 of the second control valve 129 is seated atthis point and remains so as least until the valve head of the firstcontrol valve 128 is seated.

When the shut-off valve V is closed, solvent automatically flows intothe control valve 128 as previously explained and into the spray systemthrough passage 122, thereby flushing the system of paint B. After asufficient purging interval, the control valve 128 is deactivated,thereby stopping the flow of solvent into the system, and the secondcontrol valve 129 is activated. At this point, the shut-off valve V forpaint A is open, and paint A flows through the system.

While the control valve 129 is supplying paint A to the system, thepaint supply line 123 can be disconnected from the paint inletconnection 130 for the first control valve 128, and supply line 131 fora third paint, paint C, can be connected thereto. A shut-off valve V forpaint C can now be opened and paint C is ready to be supplied as soon asthe painting cycle with paint A has been completed and the system hasbeen purged ofpaint A. It should be noted that this twovalve paintsupply system can be used to supply any number of different color ofpaint and is very efficient and economical to install and operate.

The control valve of the invention is very versatile in that it may beused effectively in manually operated, semi-automated and fullyautomated spray paint installations. It can be used effectively insystems wherein it is desired or economically advantageous to supplymore than one color of paint per valve, and can also be provided withrecirculating means when used in systems wherein a separate controlvalve is provided for each color of paint.

The control valve of the invention incorporates structural innovationswhich contribute to its versatility and simplified operation. Asimplified and convenient means is provided for actuating a valve thatfails during its paint spraying cycle. This means permits the disabledvalve to continue supplying paint and delays its repair until aninactive period. This innovation could substantially reduce theoperational cost of multi-color paint spray systems of this type sincebreakdown of a paint supply valve during operation does not necessitatea production line shut-down while the valve is being repaired.

in conjunction with the means for activating a disabled valve, theinvention also provides means for indicating an operational valve. Thismeans permits an interested party to immediately visually determinewhether an individual valve in the system is .active or not.

The invention also provides a two valve system for supplying three ormore different color paints, that does not require a separate purgingfluid valve thereby resulting in a simplified, less costly installation.This system may be operated on a semiautomated basis by supplying paintto the valve at a higher pressure than the solvent and providing checkvalves in the paint and solvent inlets. in such an installation, thesolvent flushing cycle is automatically initiated by shutting ofi thepaint supply thereby resulting in a simplier and easier to operatesystem.

In accordance with the invention, a supply system combining theadvantages of control valves designed to supply a single color paint andthose designed to supply a plurality of different color paints may beutilized. This is accomplished by providing a plurality of controlvalves continuously serving an equal number of regularly used paintcolors with a pair of control valves arranged in the manner of valves28, 29 of FIGS. 2-3 or valves 128, 129 of FIG. 6, to handle a largervariety of less frequently used colors.

I claim:

1. A system for supplying paint in a multicolor paint spray installationcomprising a. a plurality of paint supply valves connected to form aflow passage at least part of which is defined by the valve head of eachrespective valve,

b. each of said paint supply valves having communicating paint andsolvent inlet means located upstream from said flow passage,

c. said solvent inlet means being positioned to supply solvent to allvalve surfaces contacted by paint supplied by said paint inlet means,

d. means for selectively supplying solvent at a first predeterminedpressure to each of said solvent supply means,

e. means for selectively supplying paint at a second predeterminedpressure to each of said paint supply means.

2. The paint supply system of claim 1 wherein a. said solvent inletmeans is located upstream of said paint inlet means.

3. The paint supply system of claim 1 wherein a. said solvent inletmeans includes a check valve preventing fluid from flowing from thevalve toward the solvent supply, and

b. said first predetermined pressure is less than said secondpredetermined pressure, thereby preventing the flow of solvent into thevalve while paint is being supplied and automatically causing the flowof solvent into the valve when paint is not being supplied to the valve.

4. A system for supplying paint in a multicolor spray paint installationcomprising a. a paint supply conduit,

b. a paint supply valve communicating with said conduit,

c. paint inlet means communicating with said supply valve upstream fromsaid paint supply conduit, and

d. solvent inlet means communicating with said supply valve upstreamfrom said supply conduit,

e. said solvent supply means positioned to supply solvent to all valvesurfaces contacted by paint supplied by said paint supply means.

5 The system of claim 4 wherein a. said solvent supply means is disposedupstream from said paint supply means.

6. The system of claim 4 wherein a. a plurality of said paint supplyvalves are in parallel communication with said paint supply conduit.

7. A paint supply valve for supplying paint in a multicolor spray paintinstallation comprising a. a hollow valve housing having a valve seat onits lower end,

b. a longitudinally movable valve stem disposed in said valve housing,

0. said valve stem having a valve head on its lower end cooperating withsaid valve seat,

d. paint inlet means communicating with said hollow valve housing, and

. solvent inlet means communicating with said hollow valve housing,

said solvent inlet means being disposed to supply solvent to all valvesurfaces contacted by paint supplied by said paint inlet means.

The valve of claim 7 wherein said solvent inlet communicates with saidhollow valve housing upstream from said paint inlet means.

. A supply valve for a paint spray installation, comprising a hollowvalve housing having a valve seat on its lower end,

b. a longitudinally movable valve stem disposed in said valve housing,

. said valve stem having a valve head on its lower end cooperating withsaid valve seat,

d. means in said valve housing forming a plurality of passages, eachcommunicating with the interior of said valve housing,

. fluid actuated means connected to said valve stem for seating andunseating said valve head in response to control fluid pressure,indicator means associated with said fluid actuated means for indicatingwhether the valve head is seated, and

g. manually operated means associated with 'said indicator means forunseating said valve head.

10. The supply valve of claim 9 further characterized by a. saidindicator means comprising a longitudinally movable indicator stemconnected to said fluid actuated means, and

b. said indicator stem indicating whether the valve head is seatedbymoving in response to longitudinal movement of the valve stem.

operated means comprises a. a sleevelike element surrounding saidindicator stem,

b. a closed end cap threadedly secured to said sleevelike element,

c. a spacer member removably disposed on said sleevelike element tolimit the extent of threaded application of said thereon,

d. said indicator stem being movably disposed in said sleevelike elementto substantially abut against the closed end of said cap when the valvehead is seated,

e. said cap being effective to displace said indicator stem and therebymove said valve head to an unsealed positron.

12. The supply valve of claim 9 further including a. a flow housingcooperating with said valve housing and having a transverse flow passagetherein defined in part by said valve head,

b. said flow housing having means adjacent the ends of the flow passagetherein for connection to the flow housing of an adjacent similar valveto thereby form an elongated flow passage.

13. The supply valve of claim 9 further including a. a flow housingcooperating with said valve housing and having a longitudinal flowpassage therein, one end of which is defined in part by said valve head,

b. said flow housing having means adjacent the open end of saidlongitudinal flow passage for connection to the valve housing of anothersimilar valve,

0. said flow housing having means forming a transverse flow passagecommunicating with said longitudinal flow passage.

1. A system for supplying paint in a multicolor paint spray installationcomprising a. a plurality of paint supply valves connected to form aflow passage at least part of which is defined by the valve head of eachrespective valve, b. each of said paint supply valves havingcommunicating paint and solvent inlet means located upstream from saidflow passage, c. said solvent inlet means being positioned to supplysolvent to all valve surfaces contacted by paint supplied by said paintinlet means, d. means for selectively supplying solvent at a firstpredetermined pressure to each of said solvent supply means, e. meansfor selectively supplying paint at a second predetermined pressure toeach of said paint supply means.
 2. The paint supply system of claim 1wherein a. said solvent inlet means is located upstream of said paintinlet means.
 3. The paint supply system of claim 1 wherein a. saidsolvent inlet means includes a check valve preventing fluid from flowingfrom the valve toward the solvent supply, and b. said firstpredetermined pressure is less than said second predetermined pressure,thereby preventing the flow of solvent into the valve while paint isbeing supplied and automatically causing the flow of solvent into thevalve when paint is not being supplied to the valve.
 4. A system forsupplying paint in a multicolor spray paint installation comprising a. apaint supply conduit, b. a paint supply valve communicating with saidconduit, c. paint inlet means communicating with said supply valveupstream from said paint supply conduit, and d. solvent inlet meanscommunicating with said supply valve upstream from said supply conduit,e. said solvent supply means positioned to supply solvent to all valvesurfaces contacted by paint supplied by said paint supply means.
 5. Thesystem of claim 4 wherein a. said solvent supply means is disposedupstream from said paint supply means.
 6. The system of claim 4 whereina. a plurality of said paint supply valves are in parallel communicationwith said paint supply conduit.
 7. A paint supply valve for supplyingpaint in a multicolor spray paint installation comprising a. a hollowvalve housing having a valve seat on its lower end, b. a longitudinallymovable valve stem disposed in said valve housing, c. said valve stemhaving a valve head on its lower end cooperating with said valve seat,d. paint inlet means communicating with said hollow valve housing, ande. solvent inlet means communicating with said hollow valve housing, f.said solvent inlet means being disposed to supply solvent to all valvesurfaces contacted by paint supplied by said paint inlet means.
 8. Thevalve of claim 7 wherein a. said solvent inlet communicates with saidhollow valve housing upstream from said paint inlet means.
 9. A supplyvalve for a paint spray installation, comprising a. a hollow valvehousing having a valve seat on its lower end, b. a longitudinallymovable valve stem disposed in said valve housing, c. said valve stemhaving a valve head on its lower end cooperating with said valve seat,d. means in said valve housing forming a plurality of passages, eachcommunicating with the interior of said valve housing, e. fluid actuatedmeans connected to said valve stem for seating and unseating said valvehead in response to control fluid pressure, f. indicator meansassociated with said fluid actuated means for indicating whether thevalve head is seated, and g. manually operated means associated withsaid indicator means for unseating said valve head.
 10. The supply valveof claim 9 further characterized by a. said indicator means comprising alongitudinally movable indicator stem connected to said fluid actuatedmeans, and b. said indicator stem indicating whether the valve head isseated By moving in response to longitudinal movement of the valve stem.11. The supply valve of claim 10 wherein the manually operated meanscomprises a. a sleevelike element surrounding said indicator stem, b. aclosed end cap threadedly secured to said sleevelike element, c. aspacer member removably disposed on said sleevelike element to limit theextent of threaded application of said cap thereon, d. said indicatorstem being movably disposed in said sleevelike element to substantiallyabut against the closed end of said cap when the valve head is seated,e. said cap being effective to displace said indicator stem and therebymove said valve head to an unseated position.
 12. The supply valve ofclaim 9 further including a. a flow housing cooperating with said valvehousing and having a transverse flow passage therein defined in part bysaid valve head, b. said flow housing having means adjacent the ends ofthe flow passage therein for connection to the flow housing of anadjacent similar valve to thereby form an elongated flow passage. 13.The supply valve of claim 9 further including a. a flow housingcooperating with said valve housing and having a longitudinal flowpassage therein, one end of which is defined in part by said valve head,b. said flow housing having means adjacent the open end of saidlongitudinal flow passage for connection to the valve housing of anothersimilar valve, c. said flow housing having means forming a transverseflow passage communicating with said longitudinal flow passage.